bluebluesoda
e3c2b851e4
The key bar carries only what a browser will not hand over: Ctrl+C, Ctrl+Z, Ctrl+D, Escape, Tab and the arrows. It is a fallback, not the way to use the terminal — typing works for everything else, and the bar deliberately does not take focus so the keyboard keeps it. The arrow buttons ask the emulator for the sequence, so they follow the mode a full-screen program requested just like the real keys do. Paste was broken on Windows and Linux. Ctrl+V fell through to the control-key mapping and sent 0x16 with preventDefault, so the browser never got to fire a paste event, and Shift+Insert did the same with the Insert sequence. Both, and Ctrl+Shift+Insert, are now left to the platform; Cmd+V on macOS already worked. The control keys were wrong in a way only running it showed: a control byte cannot be written into an HTML attribute, so data-raw="\u0003" arrived as six literal characters and the buttons typed them instead of sending them. They carry a name now and the byte is looked up in JavaScript. Verified against a real container: the bar's bytes (003, 032, 004, 033, ESC[A-D), arrows inside less, Tab completion, Ctrl+V and Shift+Insert pasting, Enter running a two-line paste, and Ctrl+C copying when something is selected.
3.5 KiB
Web SSH
A terminal in the browser: a shell inside the user's own container, opened from the Machine card (next to Start / Stop / Restart) in the user panel.
It is not an SSH client. The container runs on the panel host, so the panel talks to it through the Incus exec API over the daemon's unix socket, with a PTY. Nothing listens on the container side, there are no keys to hand out, and there is no extra network path to arrange.
Shape of it
- Its own window. The button opens a separate browser window rather than a dialog, so it can be dragged to any size, moved to another screen or maximised. It remembers the size it was last dragged to and reopens that way.
- Root shell. The shell runs as root inside the account's own container, which is the same access the user already has over SSH. The container is always taken from the session: a client cannot name a container it does not own.
- One account, two shells. A third connection is offered the option to close the others instead of being refused, which is also how a slot held by a closed window is reclaimed.
Surviving a bad connection
The panel is often reached from far away, so the browser side is built to survive the link rather than to be torn down by it.
- Liveness. The server pings every 20 seconds and treats 60 seconds of silence as gone. The browser answers pings from its network stack, so this works in a backgrounded tab too, and a connection that disappears without saying so is noticed in about a minute.
- Reconnect. The page hears a small heartbeat the server sends alongside the protocol pings; hearing nothing for 45 seconds means the socket is dead even though it has not said so. It then reconnects with exponential backoff and jitter, up to eight attempts, after which a manual Reconnect is offered.
- Resume. The shell outlives the socket: when the client goes away the PTY keeps running for 120 seconds and its output goes into a bounded buffer (256 KiB, with a notice if anything is dropped). A client that comes back with its session token resumes the same shell — a running build, an open editor and the shell's variables are all still there.
- Redraw. A resumed terminal starts blank and is rebuilt from the buffered
output, so a full-screen program is asked to repaint itself; if one does not,
Ctrl+Lforces it. - Token. The resume token lives in
sessionStorage, so reloading the page comes back to the shell and closing the window lets it go.
Keys and the mouse
Typing works as it does in any terminal: arrows, Home/End, PageUp/PageDown, Insert/Delete, Tab, Escape and the function keys all send what a terminal sends, and the arrows follow the mode a full-screen program asks for.
A small bar above the terminal carries the few keys a browser keeps for itself (Ctrl+C, Ctrl+Z, Ctrl+D, Escape, Tab and the arrows), so they are never out of reach.
Copy and paste use the platform's own shortcuts — Cmd+C/Cmd+V, Ctrl+V, Shift+Insert — and the browser's right-click menu. Pasting a block of several lines is handed to the shell exactly as the shell asked for it: a shell that enables bracketed paste shows the text in its edit buffer first.
Turning it off
vps config set panel.web_ssh false
The panel restarts and the feature is off: the button is not rendered, and the
terminal page, its script and the terminal connection all refuse. true (the
default) turns it back on. A configuration written before this feature existed
comes out enabled.